Android：方向传感器

public class MainActivity extends Activity {

    private ImageView imageView;

    private SensorManager manager;

    private SensorListener listener = new SensorListener();

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        

        imageView = (ImageView) this.findViewById(R.id.imageView);
        imageView.setKeepScreenOn(true);

        manager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);

    }

    @Override

    protected void onResume() {
        Sensor sensor = manager.getDefaultSensor(Sensor.TYPE_ORIENTATION);

        manager.registerListener(listener, sensor, SensorManager.SENSOR_DELAY_GAME);

        super.onResume();

    }

    @Override

    protected void onPause() {
        manager.unregisterListener(listener);

        super.onPause();

    }

    

    private final class SensorListener implements SensorEventListener{

        private float predegree = 0;

        public void onSensorChanged(SensorEvent event) {

            float degree = event.values[0];//存放了方向值 90

            RotateAnimation animation = new RotateAnimation(predegree, -degree,

                    Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);

            animation.setDuration(200);

            imageView.startAnimation(animation);

            predegree = -degree;

        }

        public void onAccuracyChanged(Sensor sensor, int accuracy) {

        }

    }

    

    

}